Fuel injectors, such as, e.g., diesel fuel injectors, typically have retaining components, such as, e.g., a circlip, a ferrule ring, and/or the like, to retain a sealing component, such as, e.g., a D-ring, in a control valve body (CVB). During the recycling/remanufacturing process of fuel injectors, those retaining components may need to be removed. However, different retaining components require different removal processes involving different removal tools, respectively. Accordingly, there is a need for simplifying shortening the retaining component removal process.